1. Field of the Invention
This invention relates to a tapping attachment, whereby an axially directed force generated by a turret-type punch press is converted into a rotating force for advancing and turning a tap, so that an array of holes may be efficiently and inexpensively threaded through a sheet metal part, or the like.
2. Background Art
A drill press and an associated tapping unit are typically used to tap holes formed in a sheet metal part. However, a drill press is known to be slow, labor intensive and, thereby, cost inefficient. moreover, a drill press is used merely to drill and not thread holes. Therefore, the metal part is subject to multiple handling stages and to separate operational steps of drilling and then threading holes.
Tapping attachments have been used in the past with conventional punch-type presses for tapping holes formed in metal parts. However, and generally speaking, such attachments are characterized by a large size, thereby rendering them cumbersome and not suitable for use with a numerically controlled punch press. The conventional tapping attachments are also known to include a transmission that, because of its high torque requirements, is often characterized by a complex gearing arrangement and a corresponding large size. Such a large size usually requires that the tapping unit be securely bolted onto the punch press. Consequently, there is no way by which the tapping unit may be easily detached from its press for repair or replacement.
It would be preferable to have available an efficient tapping unit that has a simple transmission and no gears, is of small size and relatively low cost, and is easily attachable to a numerically controlled turret-type punch press or the like so that holes can be punched and threaded through a sheet metal part with minimal handling and in an efficient and cost saving manner.